60 research outputs found

    Tyrosine kinase signalling in breast cancer: Fibroblast growth factors and their receptors

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    The fibroblast growth factors [Fgfs (murine), FGFs (human)] constitute a large family of ligands that signal through a class of cell-surface tyrosine kinase receptors. Fgf signalling has been associated in vitro with cellular differentiation as well as mitogenic and motogenic responses. In vivo, Fgfs are critical for animal development, and some have potent angiogenic properties. Several Fgfs have been identified as oncogenes in murine mammary cancer, where their deregulation is associated with proviral insertions of the mouse mammary tumour virus (MMTV). Thus, in some mammary tumours of MMTV-infected mouse strains, integration of viral genomic DNA into the somatic DNA of mammary epithelial cells was found to have caused the inappropriate expression of members of this family of growth factors. Although examination of human breast cancers has shown an altered expression of FGFs or of their receptors in some tumours, their role in the causation of breast disease is unclear and remains controversial

    Met-Independent Hepatocyte Growth Factor-mediated regulation of cell adhesion in human prostate cancer cells

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    BACKGROUND: Prostate cancer cells communicate reciprocally with the stromal cells surrounding them, inside the prostate, and after metastasis, within the bone. Each tissue secretes factors for interpretation by the other. One stromally-derived factor, Hepatocyte Growth Factor (HGF), was found twenty years ago to regulate invasion and growth of carcinoma cells. Working with the LNCaP prostate cancer progression model, we found that these cells could respond to HGF stimulation, even in the absence of Met, the only known HGF receptor. The new HGF binding partner we find on the cell surface may help to clarify conflicts in the past literature about Met expression and HGF response in cancer cells. METHODS: We searched for Met or any HGF binding partner on the cells of the PC3 and LNCaP prostate cancer cell models, using HGF immobilized on agarose beads. By using mass spectrometry analyses and sequencing we have identified nucleolin protein as a novel HGF binding partner. Antibodies against nucleolin (or HGF) were able to ameliorate the stimulatory effects of HGF on met-negative prostate cancer cells. Western blots, RT-PCR, and immunohistochemistry were used to assess nucleolin levels during prostate cancer progression in both LNCaP and PC3 models. RESULTS: We have identified HGF as a major signaling component of prostate stromal-conditioned media (SCM) and have implicated the protein nucleolin in HGF signal reception by the LNCaP model prostate cancer cells. Antibodies that silence either HGF (in SCM) or nucleolin (on the cell surfaces) eliminate the adhesion-stimulatory effects of the SCM. Likewise, addition of purified HGF to control media mimics the action of SCM. C4-2, an LNCaP lineage-derived, androgen-independent human prostate cancer cell line, responds to HGF in a concentration-dependent manner by increasing its adhesion and reducing its migration on laminin substratum. These HGF effects are not due to shifts in the expression levels of laminin-binding integrins, nor can they be linked to expression of the known HGF receptor Met, as neither LNCaP nor clonally-derived C4-2 sub-line contain any detectable Met protein. Even in the absence of Met, small GTPases are activated, linking HGF stimulation to membrane protrusion and integrin activation. Membrane-localized nucelolin levels increase during cancer progression, as modeled by both the PC3 and LNCaP prostate cancer progression cell lines. CONCLUSION: We propose that cell surface localized nucleolin protein may function in these cells as a novel HGF receptor. Membrane localized nucleolin binds heparin-bound growth factors (including HGF) and appears upregulated during prostate cancer progression. Antibodies against nucleolin are able to ameliorate the stimulatory effects of HGF on met-negative prostate cancer cells. HGF-nucleolin interactions could be partially responsible for the complexity of HGF responses and met expression reported in the literature

    A model to explain specific cellular communications and cellular harmony:- a hypothesis of coupled cells and interactive coupling molecules

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    An experimental study of the lift and drag of single wedge sections in two dimensional transonic flow using the hydraulic analogy

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    The similarity of the differential equations of the transonic flow of a gas in two dimensions and of the flow of shallow water led to the choice of the latter as on experimental method, to determine the pressure distribution, lift and drag on wedges with total angles of 10o , 15 o and 20 o. The wedges were towed through shallow water and the wave pattern was determined by the measurement of water depth using a photographic technique. The results have been compared with theory and with wind tunnel experiments. For the 10 o and 15 o wedges the trends for a range of angles of incidence agree with the predictions from transonic small disturbance theory, whereas those for the largest wedge of 10 o semi-angle indicate that this angle is too large to expect satisfactory experimental results. The trends are also similar to those obtained by other workers in a wind tunnel

    The call to arms

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    Gift of Dr. Mary Jane Esplen.Dedicated to Lieut. Col. H.C. Becher Commanding the 7th Regiment Fusiliers. London, Ont. [note]Piano vocal ; orchestral and military band parts [instrumentation]British boys who play the war game [first line]They will march and fight [first line of chorus]F [key]Marziale [tempo]Lieutenant General Sam Hughes ; Minister of Militia, Canada (photograph) [illustration]March song [form/genre]Prof. Venuta [arranger]Wright Litho. Co. London, Ont. [lithographer ]This song may be sung without fee or license [note
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